Substituted l-benzyl-z-methyl-octahy-



Patented Oct. 4, 1955 United States Patenti 2,719,841

1 i 2 2,719,847 174 rt b if??? 1 1 2 th 1 1 2 3 4 5 pasywe1gto -enZy--mey,,,,,- S UT I-BENZYL-Z-METHYL-OCTAHY' 6,7,8-octahydroisoquinoline are dissolved in 290 parts DROISOQUINOLINES AND SALTS THEREOF by volume of acetic acid, and this solution is slowly Andre G ii Basel, Switzerland, assign. to H ff. 5 added dropwise at 0 C. into a mixture of 866 parts mann-La Roche Inc., Nutley, N. J., a corporation of by volume of 100 per cent nitric acid and 580 parts by New Jersey volume of acetic acid. After standing for 15 hours in s an ice-box, 5000 parts by volume of water are added No Drawmg' i f gi ggjg gg g 3 with cooling. The nitrate which crystallizes is filtered 10 off by suction and washed with water. Melting point Claims priority, application Switzerland December 6, 1948 196197 CL The nitrate is suspended in water and to this sus ension 10 C 260-283) is added a solution of an alkali hydroxide until fife solu- The present invention relates to a new method for tion' isdistinc tly alkaline The base which precipitates preparation of 3-hydroxy-N-methyl-morphinan which is a taken up m ether 891mm is separated powerful analgesic disclosed and claimed in copending Washed wlth ,Water, dl'led and evaporatedapplication Ser. No. 773,934, filed September 13, 1947, h methanol and Per cent now matured into Patent 2,524,855, granted October 10, hydrobromlc acld 13 d i the reaction is distinctly 1950. The invention also embraces novel intermediates The crystals which separate consist of which are useful in the'new method just referred to. F 2 The new method provided by the invention f the J; quinoline-hydrobromide. The melting point of this salt preparation of 3-hydroxy-N-methyl-morphinan may be lies at illustrated by the following scheme of reactions: 132 parts by g t of 1-(pi r h- N-CH:

IV V

According to this new method l-benzyl-2-methyl- 1,2,3,4,5,6,7,8-octahydroisoquinoline 'hydrobromide in l,2,3,4,5,6,7,8-octahydroisoquinoline (I) (Naturwissen- 1100 parts by volume of methanol are hydrogenated schaften, vol. 33, page 333, year 1946) is reacted with under normal 'or slightly elevated pressure in the presence a nitrating agent, such as nitric acid, thus yielding l-(pof 130 parts by weight of palladium charcoal (1.3 parts nitro-benzyl) 2 methyl l,2,3,4,5,6,7,8-octahydroisoby weight of palladium metal). After being separated quinoline (II) as a difiicultly soluble nitrate. In order from the catalyst, the solution is concentrated, whereto facilitate the subsequent hydrogenation, the nitrate is upon the hydrobromide of l-(p-amino-benzyl)-2-methylsuitably converted into the free base or a salt more easily 1,2,3,4,5,6,7,8-octahydroisoquinoline crystallizes. After soluble, such as the hydrobromide. The free base or the recrystallization from methanol-ether, its melting point salt obtained is then reduced, e. g., by catalytic hydroes at 216-218 C.

genation into l-(p-amino-benzyl)-2-methyl-1,2l,3,4,5,6,- 62 parts. by weight of l-(p-amino-benzyl-2-methyl- 7,8-octahydroisoquinoline or, respectively, an acid salt 3, y q y are thereof (HI). Upon diazotization of this compound III dissolved in 453 parts by volume of 3n sulfuric acid. and hydrolysis of the diazo compound formed, the l-(p- ThCSOllltiOll is diazotized at ()5 C. by means of a-SO- hydroxy-benzyl) 2 methyl-l,2,3,4,5,6,7,8-octahydrolution of 12.8 parts by weight of sodium nitrate in 100 isoquinoline (IV) is obtained. This compound ma be parts by volume of water. The ice-cold diazo solution reacted with an acid to form acid salts. Upon heating is Poured Within 20 minutes With Stirring into a miXtufe together with an acid cyclizing agent, more particularly of 300 parts by volume of concentrated sulfuric acid and with phosphoric acid or hydrobromic acid, the hydroxy 300 Parts y Volume of Water, the Operation being C011- compound IV is converted into the corresponding salt ductfid, at After Completion of the evolution of 3-hydroxy-N-methyl-mo bin (V), F o th 1 ofnitrogen, ice is added to the cooled solution. The thus obtained, the fre ba o th lt may b latter is adjusted to a weakly alkaline reaction by means pared in a manner know per of about 1100 parts by volume of concentrated ammonium The novel intermediates referred to above, which are y fi It is extracted with benzene, and the benzene embraced within th scope f th present i i are solution is evaporated in vacuo. The residue is taken l-(p-amino-benzyl)-2-methy1-1,2,3,4,5,6,7,8 octahydrop in 200 p s y volume of alcohol, h l t isoquinoline, 1 (p-hydroxy-benzyl)-2-methyl-1,2,3,4,5,- formedis adjusted to aweak congo acid reaction by 6,7,8-octahydroisoquinoline and the acid salts thereof, the i n of about 20 parts y volume of 48 p r such as the nitrate, the hydrobromide, the hydrochloride, hydrobromic acid and thereto parts by volume of the sulfate and the like. ether are added. The crystals which precipitate are u ed off nd a h ith a mi re o a e ne-al oh 4: 1. Melting point 243-246 C. The free base of the 1- (p-hydroxy-benzyl)-2-methyl-1,2,3,4,5,6,7,8 octahydroisoquinoline-hydrobromide can be obtained by making an aqueous solution oi the hydrobromide distinctly alkaline, extracting the base with methanol and evaporating the solvent. The free base melts at 113 C.

30 parts by Weight of l-(p-hydroxy-benzyl)-2-methyl- 1,2,3,4,5,6,7,S-octahydroisoquinoline are heated for 72 hours at 145 C. with 120 parts by volume of 100 per cent phosphoric acid. After cooling down, a mixture of 300 parts by volume of Water and 300 parts by volume of concentrated hydrochloric acid are poured into and the Whole is boiled under reflux for 4 hours so as to hydrolige the phosphoric acid esters which might have been formed. The solution is treated with charcoal and filtered, it is made alkaline by means of ammonium hydroxide and extracted with benzene. After the evaporation of the benzene, the residue is triturated with chloroform, the crystalline 3-hydroxy-N-rnethyl-morphinan is sucked oil and washed with a little chloroform and acetone. After recrystallization from alcohol, the 3-hydroxy-N-methyl-morphinan has its melting point at I claim:

1. A process which comprises nitrating 1-benzy1-2- methyl-1,2,3,4,5,6,7,8 octahydroisoquinoline, thereby producing 1 (p-nitro -benzyl)-2-methyl-l,2,3,4,5,6,7,8- octahydroisoquinoline; reducing the latter, thereby producing 1 (p-amino-benzy1)-2-methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline; diazotizing the latter, thereby producing 1 (p-hydroxy-benzyl)-2-methyl-1,2,3,4,5,6,7,8- tetrahydroisoquinoline; and heating the latter with an acid cyclizing agent, thereby producing 3-hydroxy-N- methyl-morphinan.

2. l-(p-nitro-benzyl) 2 methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline.

251-253 C. The hydrobromide melts at 193-195 C.,

the hydrochloride at 174-176 C. and the sulfate at 212- 214 C.

Example 2 30 parts by Weigh of l-(p-hydroxy-benzyl)-2-methyl- 1,2,3,4,5,6,7,8-octahydroisoquinoline obtained according to Example 1 are boiled under reflux for 8 hoursin 300 parts by volume of 48 per cent hydrobromic acid. The reaction solution is dried in vacuo and the residue is dissolved in 30 parts by volume of absolute alcohol. Upon addition of the same volume of ether, 3-hydroxy-N- methyl-morphinan-hydrobromide begins to crystalize. Its melting point is 193195 C. The free base melts at 251-253 C.

This application is a division of our copending application Serial No. 127,261, filed November 14, 1949, and now abandoned.

3. An acid addition salt of the compound of claim 2.

4. A nitric acid addition salt of the compound of claim 2. e

5. A hydrobromic acid addition salt of the compound of claim 2.

6 An acid addition salt of l-(p-amino-benzyD-Z- methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline.

'7. l-(p-amino-benzyl) 2 methyl 1,2,3,4,5,6,7,8- octahydroisoquinoline. e w n 8. l-(p-amino-benzyl) 2 methyl l,2,3,4,5,6,7,8- octahydroisoquinoline-hydrobromide.

9. A compound selected from the group consisting of l-(p-nitro benzyl) 2 methyl-1,2,3,4,5,6,7,8octahydroisoquinoline and acid addition salts thereof.

10. A compound selected from the group consisting of 1-(p-amino-benzyl) 2 methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline and acid addition salts thereof.

References Cited in the file of this patent ,UNITED STATES PATENTS Schnider et al. Oct. 10, 1950 OTHER REFERENCES (Oxford University Press; New York; 1942), page 404. 

1. A PROCESS WHICH COMPRISES NITRATING 1-BENZYL-2METHYL-1,2,3,4,5,6,7,8 - OCTAHYDROISQUINOLINE, THEREBY PRODUCING 1 - (P-NITRO-BENZYL)-2-METHYL-1,2,3,4,5,6,7,8OCTAHYDROISQUINOLINE; REDUCING THE LATTER, THEREBY PRODUCING 1-(P-AMINO-BENZYL)-2-METHYL-1,2,3,4,5,6,7,8-OCTAHYDROISOQUINOLINE; DIAZOTIZING THE LATTER, THEREBY PRODUCING 1 - (P-HYDROXY-BENZYL)-2-METHYL-1,2,3,4,5,6,7,8TETRAHYDROISOQUINOLINE; AND HEATING THE LATTER WITH AN ACID CYCLIZING AGENT, THEREBY PRODUCING 3-HYDROXY-NMETHYL-MORPHINAN. 